1. Technical Field
One or more embodiments of the present invention relate to a switching power supply.
2. Related Art
Japanese Unexamined Patent Publication No. 2000-350448 and Japanese Unexamined Patent Publication No. 2000-308339 disclose a switching power supply for detecting a lifespan of a smoothing capacitor based on a ripple voltage of a smoothing capacitor on a primary side or a secondary side. Japanese Unexamined Patent Publication No. 11-356036 discloses a DC (Direct Current) power supply device for predicting the lifespan of a smoothing capacitor based on the ambient temperature, the ripple current value, the lifespan characteristics data, the expected lifespan time, and the elapsed lifespan time. Japanese Unexamined Patent Publication No. 8-19247 and Japanese Unexamined Patent Publication No. 2002-112549 disclose a technique for predicting the lifespan of the switching power supply based on the ripple voltage.
Thus, various methods for predicting the lifespan of the switching power supply have been proposed. However, the method of predicting the lifespan of the switching power supply may not necessarily meet the requirement of the user. A new method for predicting the lifespan of the switching power supply is thus desired.